Design Practices for Rock Slopes and Rockfall Management (2022)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

83   A P P E N D I X C Individual Survey Responses This appendix contains individual responses for the 34 “rock slope” DOTs that responded that they have sufficient experience to complete the full questionnaire. Responses are sorted alphabetically by state abbreviation. Open-ended responses are not included. Questions that were not answered by the respondent are left blank.

84 Design Practices for Rock Slopes and Rockfall Management State: AK, Agency: Alaska DOT&PF. Title: Regional Engineering Geologist Road Miles: 12,000: Rock Slope Count Estimate: 1,500 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 60; Periodic Maintenance: 30; With rockfall mitigation and good function: 9; With rockfall mitigation and poor function: 0; Reconstructed: 1; New Construction: 0 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 25; Consultants: 75; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 15; Consultants: 85; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, informal standards have been communicated between agency geotechnical personnel. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by ADT volume. Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? Informal adoption of RCAD in 2002 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 2 2 Constructability Most Important: 1 Most Important: 1 Funding source 3 3 Long-term maintenance 3 2 Asset management 4 4 Aesthetics Least Important: 5 Least Important: 5 Life-cycle costs Least Important: 5 Least Important: 5 Resilience initiatives Least Important: 5 Least Important: 5 Risk management plans Least Important: 5 Least Important: 5 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Not applicable. Techniques used:

Individual Survey Responses 85   Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring Least Important: 5 Least Important: 5 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 4 4 Liability concerns 4 3 Risk acknowledgment Least Important: 5 Least Important: 5 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 10 0 10 Geotechnical drilling 25 25 10 Geotechnical instrumentation 10 10 0 Geophysical methods 10 10 0 Specialized rock laboratory testing 50 25 50 Oriented borehole imagery or oriented coring 10 10 10 Rock mass characterization methods 75 100 100 Stereonet and kinematic analyses 75 25 50 Deterministic slope stability models 50 25 50 Probabilistic slope stability models 50 25 50 Point cloud analysis 10 10 75 2-D Rockfall modeling and containment % 50 50 100 3-D Rockfall modeling and containment % 10 10 10 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: AL, Agency: Alabama DOT. Title: Chief Geologist Road Miles: 8,900: Rock Slope Count Estimate: 300 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 85; Periodic Maintenance: 14; With rockfall mitigation and good function: 1; With rockfall mitigation and poor function: 0; Reconstructed: 0; New Construction: 0 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 40; Consultants: 55; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation.

86 Design Practices for Rock Slopes and Rockfall Management In-House: 0; Consultants: 90; Construction contractor: 10; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, standards have been developed but not documented as formal department policy. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, we only have design standards for new cut slopes. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? 2000 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item National State Percentage of ditch containment Percentage of impact Percentage of reduction 95 95 Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 4 Constructability Most Important: 1 2 Funding source Most Important: 1 Most Important: 1 Long-term maintenance 2 Most Important: 1 Asset management 2 2 Aesthetics 4 3 Life-cycle costs 3 3 Resilience initiatives 3 3 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 3 4 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring Most Important: 1 Most Important: 1 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 3 Most Important: 1 Liability concerns 3 4 Risk acknowledgment Most Important: 1 Most Important: 1

Individual Survey Responses 87   Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 100 100 50 Geotechnical instrumentation 0 2 0 Geophysical methods 5 5 0 Specialized rock laboratory testing 25 25 50 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 10 0 50 Deterministic slope stability models 0 25 0 Probabilistic slope stability models 0 0 0 Point cloud analysis 5 0 25 2-D Rockfall modeling and containment % 0 0 0 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 50 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: AZ, Agency: Arizona DOT. Title: Geotechnical Services Manager Road Miles: 10,000: Rock Slope Count Estimate: 100 and basis of estimate: Blank Part C, Q4: Rock Slope Condition Percentages No Maintenance: 50; Periodic Maintenance: 20; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 0; Reconstructed: 15; New Construction: 10 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 25; Consultants: 75; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 10; Consultants: 90; Construction contractor: ; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Yes

88 Design Practices for Rock Slopes and Rockfall Management Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Most Important: 1 Most Important: 1 Constructability Most Important: 1 Most Important: 1 Funding source 2 2 Long-term maintenance Most Important: 1 Most Important: 1 Asset management Most Important: 1 2 Aesthetics 2 2 Life-cycle costs 2 2 Resilience initiatives 2 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Hammering out half casts on cut slopes. Removing proximal ends of rock bolts. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs Most Important: 1 Most Important: 1 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 2 2 Fiscal impacts of poor performance 2 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment Most Important: 1 Most Important: 1 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 50 100 50 Geotechnical instrumentation 10 10 0

Individual Survey Responses 89   Geophysical methods 100 100 100 Specialized rock laboratory testing 90 100 50 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 90 100 90 Deterministic slope stability models 90 90 90 Probabilistic slope stability models 90 90 90 Point cloud analysis 10 10 0 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 10 10 0 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: CA, Agency: Caltrans. Title: Senior Engineering Geologist (Specialist) Road Miles: 395,000: Rock Slope Count Estimate: 10,000 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 80; Periodic Maintenance: 19; With rockfall mitigation and good function: 1; With rockfall mitigation and poor function: 0; Reconstructed: ; New Construction: Part C, Q5: Designer percentages of new rock cut slopes. In-House: 95; Consultants: 5; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 99; Consultants: 1; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: No, we have no design standards, but we use consistent approaches to develop rock slope and rockfall mitigation designs. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q3: Do standards vary between roadway classification or other particulars? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width

90 Design Practices for Rock Slopes and Rockfall Management Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 4 Constructability Most Important: 1 Most Important: 1 Funding source 3 3 Long-term maintenance Most Important: 1 Most Important: 1 Asset management 4 4 Aesthetics 2 2 Life-cycle costs 2 2 Resilience initiatives Most Important: 1 Most Important: 1 Risk management plans 4 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 90%–100%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Removing proximal ends of rock bolts. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 4 3 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring 4 3 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 2 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment Least Important: 5 4 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 10 100 100 Rope-based reconnaissance 50 20 75 Geotechnical drilling 20 75 5 Geotechnical instrumentation 20 25 5 Geophysical methods 10 50 10 Specialized rock laboratory testing 50 50 5 Oriented borehole imagery or oriented coring 10 20 0 Rock mass characterization methods 75 50 75 Stereonet and kinematic analyses 100 0 100 Deterministic slope stability models 20 0 Probabilistic slope stability models 20 0 Point cloud analysis 75 50 90

Individual Survey Responses 91   2-D Rockfall modeling and containment % 75 0 75 3-D Rockfall modeling and containment % 20 0 20 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: CO, Agency: Central FLHD. Title: Geotechnical Engineer Road Miles: 0: Rock Slope Count Estimate: 0 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 0; Periodic Maintenance: 80; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 5; Reconstructed: 5; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 80; Consultants: 20; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 80; Consultants: 20; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, informal standards that may be applied on a project- specific basis. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by ADT volume. Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? 2016 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Slope Rating Form (USMP) Percentage of ditch containment 3 Percentage of impact 27 Percentage of reduction Roadside ditch width 3' Target scoring 95% containment Frequency of rocks reaching road We only get calls when they panic about it. Maintenance activity frequency What’s maintenance? Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 3

92 Design Practices for Rock Slopes and Rockfall Management Constructability Most Important: 1 3 Funding source 2 Most Important: 1 Long-term maintenance 2 2 Asset management 2 Most Important: 1 Aesthetics 4 Least Important: 5 Life-cycle costs 3 2 Resilience initiatives 2 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 50%–75%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Removing proximal ends of rock bolts. Other: vegetated mats, pins that catch debris and destroy the mesh. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 4 4 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 2 Liability concerns Least Important: 5 2 Risk acknowledgment 3 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 Rope-based reconnaissance 25 25 Geotechnical drilling 50 50 Geotechnical instrumentation 10 10 Geophysical methods 10 10 Specialized rock laboratory testing 50 50 Oriented borehole imagery or oriented coring Rock mass characterization methods 80 Stereonet and kinematic analyses 100 Deterministic slope stability models Probabilistic slope stability models Point cloud analysis 25 2-D Rockfall modeling and containment % 100 3-D Rockfall modeling and containment % 0 Design guides and containment % 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, as part of a larger management program. Comment: USMP, relies on partner data and knowledge.

Individual Survey Responses 93   Part F, Q2: Do you regularly engage in performance data collection efforts? Yes. Comment: We’re trying to push the USMP. Part F, Q3: Would your DOT be interested in participating as a case history? No State: CO, Agency: Colorado DOT. Title: Engineering Geologist Road Miles: 9,000: Rock Slope Count Estimate: 3,500 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 2; Periodic Maintenance: 60; With rockfall mitigation and good function: 16; With rockfall mitigation and poor function: 2; Reconstructed: 19; New Construction: 1 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 10; Consultants: 85; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 30; Consultants: 65; Construction contractor: 5; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: No, we have no design standards, but we use consistent approaches to develop rock slope and rockfall mitigation designs. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q3: Do standards vary between roadway classification or other particulars? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Federally Funded (FHWA) ER Projects Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Mitigate slopes with CRHRS score >650. Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 4 4 Constructability Most Important: 1 Most Important: 1 Funding source 4 4 Long-term maintenance 2 2 Asset management 3 2

94 Design Practices for Rock Slopes and Rockfall Management Aesthetics 2 3 Life-cycle costs 2 2 Resilience initiatives 3 2 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 75%–90%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Hammering out half casts on cut slopes. Removing proximal ends of rock bolts. Other: Consideration of alternative mitigation methods (PUR). Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 Most Important: 1 Consequence of major slope failure Most Important: 1 2 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 4 4 Risk reduction through instrumentation 3 4 Fiscal impacts of poor performance 3 2 Liability concerns 4 4 Risk acknowledgment 3 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 20 0 30 Geotechnical drilling 5 100 1 Geotechnical instrumentation 5 50 10 Geophysical methods 2 75 1 Specialized rock laboratory testing 5 75 5 Oriented borehole imagery or oriented coring 2 2 0 Rock mass characterization methods 25 95 15 Stereonet and kinematic analyses 90 10 15 Deterministic slope stability models 80 90 15 Probabilistic slope stability models 20 30 5 Point cloud analysis 80 2 85 2-D Rockfall modeling and containment % 95 100 85 3-D Rockfall modeling and containment % 5 5 10 Design guides and containment % 95 100 70 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, as part of a larger management program. Part F, Q2: Do you regularly engage in performance data collection efforts? No. Comment: CDOT is working to establish performance objectives to meet department asset management and resilience goals. Part F, Q3: Would your DOT be interested in participating as a case history? Yes

Individual Survey Responses 95   State: CT, Agency: Connecticut DOT. Title: Transportation Supervising Engineer Road Miles: 3,719: Rock Slope Count Estimate: 1,000 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 75; Periodic Maintenance: 10; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 0; Reconstructed: 5; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 20; Consultants: 75; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 50; Consultants: 25; Construction contractor: 25; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, informal standards have been communicated between agency geotechnical personnel. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? N/A or pre-1988 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item All State Roadways Percentage of ditch containment 0 (rarely use) Percentage of impact 100 Percentage of reduction 0 Roadside ditch width Typically controlled by highway geometrics and ROW Target scoring N/A Frequency of rocks reaching road 1 every 5 years Maintenance activity frequency 3 every year Probabilistic measures <1% Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5 Constructability Most Important: 1 Most Important: 1 Funding source 4 Long-term maintenance 2 3 Asset management 3 3 Aesthetics 3 3 Life-cycle costs 3 3 Resilience initiatives 3 3 Risk management plans 3 3

96 Design Practices for Rock Slopes and Rockfall Management Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: . Techniques used: . Other: Scarifying drill lines. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 Most Important: 1 Consequence of major slope failure Most Important: 1 3 Maintenance frequency and costs 2 3 Risk reduction through visual monitoring 2 3 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 3 3 Liability concerns 2 3 Risk acknowledgment 2 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 100 100 10 Geotechnical instrumentation 0 0 0 Geophysical methods 25 50 0 Specialized rock laboratory testing 25 100 0 Oriented borehole imagery or oriented coring 1 0 0 Rock mass characterization methods 100 100 0 Stereonet and kinematic analyses 0 0 0 Deterministic slope stability models 0 0 0 Probabilistic slope stability models 0 0 0 Point cloud analysis 0 0 0 2-D Rockfall modeling and containment % 0 0 0 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 0 0 0 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: HI, Agency: Hawaii DOT - Highways. Title: Geotechnical Section Head Road Miles: 1,000: Rock Slope Count Estimate: 0 and basis of estimate: Blank Part C, Q4: Rock Slope Condition Percentages No Maintenance: ; Periodic Maintenance: ; With rockfall mitigation and good function: ; With rockfall mitigation and poor function: ; Reconstructed: ; New Construction: Part C, Q5: Designer percentages of new rock cut slopes.

Individual Survey Responses 97   In-House: ; Consultants: ; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: ; Consultants: ; Construction contractor: ; Manufacturer: Part D, Q1: Adoption of minimum design standards: Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Part D, Q3: Do standards vary between roadway classification or other particulars? Part D, Q4: Standards applicable to appurtenant facilities? Part D, Q5: What year were standards adopted? Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Constructability Funding source Long-term maintenance Asset management Aesthetics Life-cycle costs Resilience initiatives Risk management plans Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: . Techniques used: Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure Consequence of major slope failure Maintenance frequency and costs Risk reduction through visual monitoring Risk reduction through instrumentation Fiscal impacts of poor performance Liability concerns Risk acknowledgment

98 Design Practices for Rock Slopes and Rockfall Management Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance Rope-based reconnaissance Geotechnical drilling Geotechnical instrumentation Geophysical methods Specialized rock laboratory testing Oriented borehole imagery or oriented coring Rock mass characterization methods Stereonet and kinematic analyses Deterministic slope stability models Probabilistic slope stability models Point cloud analysis 2-D Rockfall modeling and containment % 3-D Rockfall modeling and containment % Design guides and containment % Part F, Q1: Do you have performance measures specific to rock slopes? Part F, Q2: Do you regularly engage in performance data collection efforts? Part F, Q3: Would your DOT be interested in participating as a case history? State: IA, Agency: Iowa DOT. Title: Transportation Engineer Specialist Road Miles: 9,617: Rock Slope Count Estimate: 200 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 85; Periodic Maintenance: 5; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 5; Reconstructed: ; New Construction: Part C, Q5: Designer percentages of new rock cut slopes. In-House: 90; Consultants: 5; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 90; Consultants: 5; Construction contractor: 5; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? 1995

Individual Survey Responses 99   Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item All Primary Highways (Interstate, U.S., and State) Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width 10' Target scoring Frequency of rocks reaching road Maintenance activity frequency Yearly in spring, or as needed Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Most Important: 1 Most Important: 1 Constructability Most Important: 1 Most Important: 1 Funding source 3 3 Long-term maintenance 3 3 Asset management 4 4 Aesthetics 2 2 Life-cycle costs 2 2 Resilience initiatives Least Important: 5 Least Important: 5 Risk management plans Least Important: 5 Least Important: 5 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Not applicable. Techniques used: Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 Most Important: 1 Consequence of major slope failure Least Important: 5 Least Important: 5 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 0 Least Important: 5 Liability concerns 4 4 Risk acknowledgment Least Important: 5 Least Important: 5 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 25 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 100 100 50 Geotechnical instrumentation 0 0 0 Geophysical methods 0 0 0

100 Design Practices for Rock Slopes and Rockfall Management Specialized rock laboratory testing 100 100 50 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 100 100 50 Stereonet and kinematic analyses 0 0 0 Deterministic slope stability models 0 0 0 Probabilistic slope stability models 0 0 0 Point cloud analysis 0 0 0 2-D Rockfall modeling and containment % 0 0 0 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 0 0 0 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? Not applicable Part F, Q3: Would your DOT be interested in participating as a case history? No State: ID, Agency: Idaho Transportation Department. Title: District Geologist Road Miles: 6,137: Rock Slope Count Estimate: 500 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 10; Periodic Maintenance: 50; With rockfall mitigation and good function: 20; With rockfall mitigation and poor function: 3; Reconstructed: 15; New Construction: 2 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 20; Consultants: 79; Construction contractor: 1; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 30; Consultants: 64; Construction contractor: 5; Manufacturer: 1 Part D, Q1: Adoption of minimum design standards: Yes, informal standards that may be applied on a project- specific basis. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by another metric (describe below). Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? The only standard is informal % containment, 1995. Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Interstate NHS & Major State Highways Percentage of ditch containment 90 90 Percentage of impact Percentage of reduction 95 95 Roadside ditch width Target scoring N/A; different systems used in different districts. N/A; different systems used in different districts.

Individual Survey Responses 101   Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Most Important: 1 Least Important: 5 Constructability 2 Most Important: 1 Funding source Least Important: 5 Most Important: 1 Long-term maintenance 4 3 Asset management Least Important: 5 3 Aesthetics 4 4 Life-cycle costs Least Important: 5 Least Important: 5 Resilience initiatives Least Important: 5 Least Important: 5 Risk management plans Least Important: 5 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Other: biomechanical stabilizing and using low-visibility mesh. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring Least Important: 5 Least Important: 5 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 4 4 Liability concerns Least Important: 5 4 Risk acknowledgment Least Important: 5 Least Important: 5 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 25 10 30 Geotechnical drilling 25 60 30 Geotechnical instrumentation 15 10 10 Geophysical methods 20 20 30 Specialized rock laboratory testing 35 15 30 Oriented borehole imagery or oriented coring 5 10 5 Rock mass characterization methods 25 50 30 Stereonet and kinematic analyses 25 10 30 Deterministic slope stability models 30 10 100 Probabilistic slope stability models 0 Point cloud analysis 20 20 2-D Rockfall modeling and containment % 100 10 80

102 Design Practices for Rock Slopes and Rockfall Management 3-D Rockfall modeling and containment % 0 Design guides and containment % 40 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Comment: Geologists, who are few, have done the monitoring; with some districts having no geologists, little tracking has been done. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? State: KY, Agency: Kentucky Transportation Cabinet. Title: Geologist Registered Supervisor Road Miles: 60,000: Rock Slope Count Estimate: 5,270 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 15; Periodic Maintenance: 75; With rockfall mitigation and good function: 3; With rockfall mitigation and poor function: 1; Reconstructed: 1; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 54; Consultants: 40; Construction contractor: 5; Manufacturer: 1 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 65; Consultants: 15; Construction contractor: 10; Manufacturer: 10 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by highway functional classification (interstate, major arterial, minor collector, etc.). Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? +/-1985 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Interstate/Parkways (When Full Safety Is Required) U.S. or State Route Percentage of ditch containment Varies Percentage of impact Percentage of reduction Roadside ditch width 18' minimum 12'–14' minimum Target scoring Frequency of rocks reaching road Maintenance activity frequency Low Low Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important.

Individual Survey Responses 103   Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5 Constructability Most Important: 1 Most Important: 1 Funding source 3 3 Long-term maintenance 2 2 Asset management Most Important: 1 Most Important: 1 Aesthetics Least Important: 5 Least Important: 5 Life-cycle costs 2 2 Resilience initiatives Most Important: 1 Most Important: 1 Risk management plans Most Important: 1 Most Important: 1 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Not applicable. Techniques used: Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 0 Most Important: 1 Liability concerns 2 2 Risk acknowledgment Most Important: 1 Most Important: 1 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 99 99 Rope-based reconnaissance 1 1 1 Geotechnical drilling 50 99 50 Geotechnical instrumentation 1 1 1 Geophysical methods 1 1 1 Specialized rock laboratory testing 1 1 1 Oriented borehole imagery or oriented coring 1 1 1 Rock mass characterization methods 50 99 50 Stereonet and kinematic analyses 1 1 1 Deterministic slope stability models 10 10 10 Probabilistic slope stability models 0 1 1 Point cloud analysis 1 1 25 2-D Rockfall modeling and containment % 10 10 99 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No

104 Design Practices for Rock Slopes and Rockfall Management Part F, Q3: Would your DOT be interested in participating as a case history? No State: MA, Agency: MassDOT Title: Geotechncial Engineer Road Miles: 36,000: Rock Slope Count Estimate: 50 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: ; Periodic Maintenance: ; With rockfall mitigation and good function: ; With rockfall mitigation and poor function: ; Reconstructed: ; New Construction: Part C, Q5: Designer percentages of new rock cut slopes. In-House: ; Consultants: 100; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 10; Consultants: 90; Construction contractor: ; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 2010 is the first year I can find it, but it may be older. Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5 Constructability Most Important: 1 Most Important: 1 Funding source Most Important: 1 Most Important: 1 Long-term maintenance 3 2 Asset management Aesthetics Least Important: 5 Least Important: 5 Life-cycle costs Resilience initiatives Risk management plans

Individual Survey Responses 105   Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Not applicable. Techniques used: Other: Not aware of aesthetics considerations. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs Risk reduction through visual monitoring Risk reduction through instrumentation Fiscal impacts of poor performance Liability concerns Risk acknowledgment Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 Rope-based reconnaissance 0 0 Geotechnical drilling 50 10 Geotechnical instrumentation 0 0 Geophysical methods 5 0 Specialized rock laboratory testing 10 Oriented borehole imagery or oriented coring 0 0 Rock mass characterization methods 0 Stereonet and kinematic analyses 50 100 Deterministic slope stability models 50 Probabilistic slope stability models Point cloud analysis 0 2-D Rockfall modeling and containment % 3-D Rockfall modeling and containment % 0 Design guides and containment % Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: ME, Agency: Maine DOT. Title: Senior Geotechnical Engineer Road Miles: 23,400: Rock Slope Count Estimate: 75 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 80; Periodic Maintenance: 5; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 0; Reconstructed: 5; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes.

106 Design Practices for Rock Slopes and Rockfall Management In-House: 10; Consultants: 85; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 10; Consultants: 80; Construction contractor: 0; Manufacturer: 10 Part D, Q1: Adoption of minimum design standards: No, we have no design standards, but we use consistent approaches to develop rock slope and rockfall mitigation designs. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by highway functional classification (interstate, major arterial, minor collector, etc.). Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item New Rock Cut Existing Rock Cut Percentage of ditch containment 90 80 Percentage of impact 97 10 Percentage of reduction 0 50 Roadside ditch width 10' minimum 6' minimum Target scoring N/A N/A Frequency of rocks reaching road 2 times per year 2 times per year Maintenance activity frequency Annual Annual Probabilistic measures Not established Not established Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 2 2 Constructability Most Important: 1 Most Important: 1 Funding source 2 2 Long-term maintenance Most Important: 1 Most Important: 1 Asset management 3 3 Aesthetics 2 Most Important: 1 Life-cycle costs Most Important: 1 2 Resilience initiatives 4 4 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 25%–50%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs Most Important: 1 2 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation 4 4

Individual Survey Responses 107   Fiscal impacts of poor performance 3 2 Liability concerns 2 2 Risk acknowledgment 3 4 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 90 90 95 Geotechnical drilling 100 100 100 Geotechnical instrumentation 75 50 45 Geophysical methods 95 95 95 Specialized rock laboratory testing 95 95 95 Oriented borehole imagery or oriented coring 80 60 50 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 80 50 50 Deterministic slope stability models 100 100 100 Probabilistic slope stability models 100 100 100 Point cloud analysis 75 50 60 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 20 20 20 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: MN, Agency: Minnesota DOT. Title: Engineering Geologist Road Miles: 11,696: Rock Slope Count Estimate: 750 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 75; Periodic Maintenance: 15; With rockfall mitigation and good function: 2; With rockfall mitigation and poor function: 1; Reconstructed: 1; New Construction: 6 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 50; Consultants: 25; Construction contractor: 25; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 50; Consultants: 25; Construction contractor: 25; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation.

108 Design Practices for Rock Slopes and Rockfall Management Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? 1985 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Rockfall Mitigation Along Trunk Highways Percentage of ditch containment 90–95 Percentage of impact 99 Percentage of reduction 0 Roadside ditch width Dependent on rock slope height, cut angle, and discontinuities Target scoring N/A Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 4 4 Constructability Most Important: 1 Most Important: 1 Funding source 3 3 Long-term maintenance Most Important: 1 Most Important: 1 Asset management Most Important: 1 Most Important: 1 Aesthetics 2 2 Life-cycle costs 2 2 Resilience initiatives 2 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 50%–75%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Other: One of our districts used a “Rustic Slope” special provision. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 3 4 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 2 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment 3 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation.

Individual Survey Responses 109   Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 15 5 15 Geotechnical drilling 100 100 10 Geotechnical instrumentation 5 5 5 Geophysical methods 25 100 5 Specialized rock laboratory testing 80 100 5 Oriented borehole imagery or oriented coring 20 20 5 Rock mass characterization methods 100 100 10 Stereonet and kinematic analyses 10 10 5 Deterministic slope stability models 10 10 5 Probabilistic slope stability models 10 10 5 Point cloud analysis 80 25 85 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 5 5 5 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: MT, Agency: Montana DOT. Title: Geotechnical Manager Road Miles: 12,923: Rock Slope Count Estimate: 1,869 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 50; Periodic Maintenance: 39; With rockfall mitigation and good function: 3; With rockfall mitigation and poor function: 5; Reconstructed: 2; New Construction: 1 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 70; Consultants: 30; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 30; Consultants: 70; Construction contractor: ; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, informal standards that may be applied on a project- specific basis. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, between highway system designation (National Highway System, state highway system, etc.). Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent.

110 Design Practices for Rock Slopes and Rockfall Management Item Interstate Primary Highway Percentage of ditch containment 95–98 92–95 Percentage of impact 0 99 Percentage of reduction Roadside ditch width Target scoring RHRS, incidents, and maintenance RHRS, incidents, and maintenance Frequency of rocks reaching road Few Few to some Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 4 4 Constructability 3 3 Funding source 2 2 Long-term maintenance Most Important: 1 Most Important: 1 Asset management 3 2 Aesthetics Least Important: 5 3 Life-cycle costs 2 2 Resilience initiatives 4 3 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 25%–50%. Techniques used: Staining of steel products. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 3 Consequence of major slope failure Most Important: 1 2 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation 4 3 Fiscal impacts of poor performance 0 Most Important: 1 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment Most Important: 1 Most Important: 1 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 10 10 30 Geotechnical drilling 60 90 0 Geotechnical instrumentation 10 20 0 Geophysical methods 20 50 0 Specialized rock laboratory testing 30 50 10 Oriented borehole imagery or oriented coring 10 10 0

Individual Survey Responses 111   Rock mass characterization methods 60 80 30 Stereonet and kinematic analyses 80 20 50 Deterministic slope stability models 20 Probabilistic slope stability models 20 Point cloud analysis 10 10 2-D Rockfall modeling and containment % 90 50 100 3-D Rockfall modeling and containment % 0 0 10 Design guides and containment % 90 90 90 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Comment: We have a Rockfall Asset Management Plan in place. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: NC, Agency: North Carolina DOT. Title: Regional Geological Engineer Road Miles: 80,000: Rock Slope Count Estimate: 200 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 30; Periodic Maintenance: 30; With rockfall mitigation and good function: 20; With rockfall mitigation and poor function: ; Reconstructed: 10; New Construction: 10 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 80; Consultants: 20; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 90; Consultants: ; Construction contractor: 10; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, informal standards have been communicated between agency geotechnical personnel. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, we only have design standards for new cut slopes. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by another metric (describe below). Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 2016 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item New Primary Two-Lane U.S. or State Highway Secondary Roadway Mitigation Percentage of ditch containment 90 Noted, not formally assessed. Modeled if fence catchment is desired mitigation approach: 90. Percentage of impact 0 Noted, not formally assessed. Modeled if fence catchment is desired mitigation approach: 90.

112 Design Practices for Rock Slopes and Rockfall Management Percentage of reduction 90 0 Roadside ditch width Adopted roadway template is 10'. Not a specific function of Geotech. Geotech may add additional width as catchment. May be modeled if borderline acceptable as is. Target scoring Slopes are scored in GAM system. No adopted target. Frequency of rocks reaching road Documented for future consideration. No allowable value for consideration otherwise. May be modeled if determined to be warning of larger-scale future event. Maintenance activity frequency Informal consideration. Does enter into GAM database. GAM database not currently used Probabilistic measures Okay if predicted to impede shoulder but not actual travel lane (uses paved shoulder as catchment width). Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 4 Constructability 3 Most Important: 1 Funding source Most Important: 1 Most Important: 1 Long-term maintenance Most Important: 1 2 Asset management 4 Most Important: 1 Aesthetics 3 3 Life-cycle costs 2 3 Resilience initiatives Least Important: 5 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Other: Staining slope shotcrete, slope geometry to either match existing or minimize visual impact. Oddly, adding half casts in shotcrete to match existing intact half casts [. . .]. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 2 Risk reduction through visual monitoring Least Important: 5 2 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 0 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment 2 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation.

Individual Survey Responses 113   Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 10 0 30 Geotechnical drilling 50 75 0 Geotechnical instrumentation 0 0 5 Geophysical methods 5 5 0 Specialized rock laboratory testing 10 10 0 Oriented borehole imagery or oriented coring 5 5 0 Rock mass characterization methods 75 50 20 Stereonet and kinematic analyses 75 25 90 Deterministic slope stability models 50 75 50 Probabilistic slope stability models 0 0 0 Point cloud analysis 5 0 20 2-D Rockfall modeling and containment % 25 10 50 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 50 50 0 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: NH, Agency: New Hampshire DOT. Title: Engineering Geologist Road Miles: ; Rock Slope Count Estimate: 381 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 5; Periodic Maintenance: 50; With rockfall mitigation and good function: 10; With rockfall mitigation and poor function: 0; Reconstructed: 30; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 99; Consultants: 1; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 95; Consultants: 3; Construction contractor: 2; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, standards have been developed but not documented as formal department policy. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? na Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent.

114 Design Practices for Rock Slopes and Rockfall Management Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 3 Constructability Most Important: 1 Most Important: 1 Funding source Least Important: 5 Least Important: 5 Long-term maintenance 2 2 Asset management 2 2 Aesthetics 2 2 Life-cycle costs 2 2 Resilience initiatives 3 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Hammering out half casts on cut slopes. Removing proximal ends of rock bolts. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure 2 2 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 2 2 Fiscal impacts of poor performance 2 2 Liability concerns 2 2 Risk acknowledgment 3 2 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 20 80 Geotechnical drilling 80 100 5 Geotechnical instrumentation 10 Geophysical methods 10 80 80 Specialized rock laboratory testing 10 80 50 Oriented borehole imagery or oriented coring 10 80 0

Individual Survey Responses 115   Rock mass characterization methods 50 80 50 Stereonet and kinematic analyses 100 80 100 Deterministic slope stability models 80 80 50 Probabilistic slope stability models 80 80 50 Point cloud analysis 90 0 100 2-D Rockfall modeling and containment % 90 5 50 3-D Rockfall modeling and containment % 90 5 50 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? Part F, Q2: Do you regularly engage in performance data collection efforts? Part F, Q3: Would your DOT be interested in participating as a case history? State: NJ, Agency: New Jersey DOT. Title: Engineering Geologist 4 Road Miles: 12,000: Rock Slope Count Estimate: 444 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 50; Periodic Maintenance: 15; With rockfall mitigation and good function: 20; With rockfall mitigation and poor function: 0; Reconstructed: 5; New Construction: 10 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 0; Consultants: 100; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 10; Consultants: 90; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, standards have been developed but not documented as formal department policy. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? 2017 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Interstate Highway System State Highway System Percentage of ditch containment 95 95 Percentage of impact Percentage of reduction Roadside ditch width Target scoring RHRS and rockfall modeling RHRS and rockfall modeling Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures

116 Design Practices for Rock Slopes and Rockfall Management Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 2 2 Constructability 2 2 Funding source 2 2 Long-term maintenance Most Important: 1 Most Important: 1 Asset management Most Important: 1 Most Important: 1 Aesthetics Most Important: 1 Most Important: 1 Life-cycle costs 2 2 Resilience initiatives 3 3 Risk management plans Most Important: 1 Most Important: 1 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 90%–100%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Other: Revegetation; colorization of elements; use of natural materials. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 3 3 Liability concerns 2 2 Risk acknowledgment 2 2 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 20 0 20 Geotechnical drilling 100 100 100 Geotechnical instrumentation 10 Geophysical methods 100 100 100 Specialized rock laboratory testing 100 100 100 Oriented borehole imagery or oriented coring 100 100 100 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 100 100 100 Deterministic slope stability models 100 100 100 Probabilistic slope stability models Point cloud analysis 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 100 Design guides and containment % 100 100 100

Individual Survey Responses 117   Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? Yes Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: NV, Agency: Nevada DOT. Title: Geotechnical Engineer/Manager Road Miles: 2,000: Rock Slope Count Estimate: 1,500 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 33; Periodic Maintenance: 35; With rockfall mitigation and good function: 15; With rockfall mitigation and poor function: 2; Reconstructed: 10; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 40; Consultants: 60; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 40; Consultants: 60; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: No, we have no design standards, but we use consistent approaches to develop rock slope and rockfall mitigation designs. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q3: Do standards vary between roadway classification or other particulars? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Constructability Funding source Long-term maintenance Asset management

118 Design Practices for Rock Slopes and Rockfall Management Aesthetics Life-cycle costs Resilience initiatives Risk management plans Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Contouring of wire mesh/nets to the slope. Other: Color of mesh to match slope. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 4 4 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 3 3 Liability concerns 2 2 Risk acknowledgment 2 2 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 80 85 80 Rope-based reconnaissance 0 0 0 Geotechnical drilling 0 0 0 Geotechnical instrumentation 0 0 0 Geophysical methods 80 90 80 Specialized rock laboratory testing 0 0 0 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 10 0 0 Stereonet and kinematic analyses 0 0 0 Deterministic slope stability models 5 5 5 Probabilistic slope stability models 5 5 5 Point cloud analysis 5 0 0 2-D Rockfall modeling and containment % 0 0 0 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 40 70 0 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: NY, Agency: New York State DOT. Title: Professional Geologist 2

Individual Survey Responses 119   Road Miles: 50,000: Rock Slope Count Estimate: 3,218 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 80; Periodic Maintenance: 13; With rockfall mitigation and good function: 2; With rockfall mitigation and poor function: 1; Reconstructed: 2; New Construction: 2 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 100; Consultants: 0; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 100; Consultants: 0; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, standards have been developed but not documented as formal department policy. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 1988 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item All Roads Percentage of ditch containment 90 Percentage of impact 0 Percentage of reduction 0 Roadside ditch width Clear zone or drainage dependant Target scoring N/A; we use a relative risk system. Frequency of rocks reaching road Few Maintenance activity frequency Infrequent Probabilistic measures N/A Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 Most Important: 1 Constructability Most Important: 1 Most Important: 1 Funding source 2 2 Long-term maintenance Most Important: 1 2 Asset management 3 3 Aesthetics 2 2 Life-cycle costs Most Important: 1 2 Resilience initiatives 3 3 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products.

120 Design Practices for Rock Slopes and Rockfall Management Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring 4 2 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 2 2 Liability concerns 2 2 Risk acknowledgment Least Important: 5 Least Important: 5 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 5 90 5 Geotechnical instrumentation 0 0 1 Geophysical methods 5 25 0 Specialized rock laboratory testing 5 90 5 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 5 90 5 Stereonet and kinematic analyses 75 75 75 Deterministic slope stability models 10 10 10 Probabilistic slope stability models 0 0 0 Point cloud analysis 10 10 20 2-D Rockfall modeling and containment % 20 20 40 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 90 90 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, as part of a larger management program. Part F, Q2: Do you regularly engage in performance data collection efforts? Yes. Comment: Informally Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: OH, Agency: Ohio DOT. Title: Assistant Administrator, Office of Geotechnical Engineering Road Miles: 49,546: Rock Slope Count Estimate: 5,900 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 70; Periodic Maintenance: 20; With rockfall mitigation and good function: 2; With rockfall mitigation and poor function: 2; Reconstructed: 3; New Construction: 3 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 30; Consultants: 55; Construction contractor: 15; Manufacturer: 0

Individual Survey Responses 121   Part C, Q6: Designer percentages of rockfall mitigation. In-House: 50; Consultants: 40; Construction contractor: 7; Manufacturer: 3 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? 2006 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item State Highway System (No Differences in Standards for Any Classification) Percentage of ditch containment 95 Percentage of impact Percentage of reduction Roadside ditch width Varies based on geometry of slope and ditch Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 4 3 Constructability Most Important: 1 Most Important: 1 Funding source 2 2 Long-term maintenance 2 2 Asset management 3 2 Aesthetics 4 4 Life-cycle costs 2 2 Resilience initiatives 3 3 Risk management plans 3 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 4 4

122 Design Practices for Rock Slopes and Rockfall Management Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 2 2 Liability concerns 3 2 Risk acknowledgment 3 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 2 0 5 Geotechnical drilling 90 100 60 Geotechnical instrumentation 0 0 0 Geophysical methods 0 0 0 Specialized rock laboratory testing 50 90 50 Oriented borehole imagery or oriented coring 5 5 3 Rock mass characterization methods 100 100 70 Stereonet and kinematic analyses 0 0 0 Deterministic slope stability models 10 20 5 Probabilistic slope stability models 0 0 0 Point cloud analysis 70 50 70 2-D Rockfall modeling and containment % 70 70 70 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 70 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, as part of a larger management program. Comment: Our inventory rating is initially based on probability of rockfall occurrence and probability of reaching the road with additional details collected depending on risk level. Part F, Q2: Do you regularly engage in performance data collection efforts? Yes. Comment: Frequency of reinspection is based on risk rating determined during most recent inspection. Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: OR, Agency: Oregon DOT. Title: Engineering Geology Program Leader Road Miles: 8,033: Rock Slope Count Estimate: 4,060 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 0; Periodic Maintenance: 70; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 20; Reconstructed: 4; New Construction: 1 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 60; Consultants: 40; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 70; Consultants: 30; Construction contractor: ; Manufacturer:

Individual Survey Responses 123   Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 2001 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 2 2 Constructability Most Important: 1 Most Important: 1 Funding source 2 Most Important: 1 Long-term maintenance Most Important: 1 2 Asset management 2 2 Aesthetics 2 2 Life-cycle costs 3 2 Resilience initiatives 2 2 Risk management plans 4 4 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 90%–100%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Hammering out half casts on cut slopes. Removing proximal ends of rock bolts. Other: Countersinking rock bolts, introducing projections and appurtenances to provide a more “natural” look. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 2 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring 4 3 Risk reduction through instrumentation 4 3 Fiscal impacts of poor performance 2 Most Important: 1 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment 2 2

124 Design Practices for Rock Slopes and Rockfall Management Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 25 0 33 Geotechnical drilling 75 100 25 Geotechnical instrumentation 75 100 25 Geophysical methods 25 25 5 Specialized rock laboratory testing 50 25 20 Oriented borehole imagery or oriented coring 10 15 0 Rock mass characterization methods 100 100 75 Stereonet and kinematic analyses 95 75 75 Deterministic slope stability models 100 100 75 Probabilistic slope stability models 100 100 75 Point cloud analysis 50 25 5 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? Yes Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: PA, Agency: PennDOT. Title: Regional Geotechnical Engineer Road Miles: 43,000: Rock Slope Count Estimate: 10,000 and basis of estimate: Partial Inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 10; Periodic Maintenance: 70; With rockfall mitigation and good function: 10; With rockfall mitigation and poor function: 0; Reconstructed: 5; New Construction: 5 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 20; Consultants: 75; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 20; Consultants: 75; Construction contractor: 5; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by another metric (describe below).

Individual Survey Responses 125   Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 2018 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item All Percentage of ditch containment 95 Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 3 Constructability 2 2 Funding source Most Important: 1 2 Long-term maintenance 3 3 Asset management 3 3 Aesthetics 3 3 Life-cycle costs 3 3 Resilience initiatives 4 4 Risk management plans 4 4 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 25%–50%. Techniques used: Removing proximal ends of rock bolts. Other: Sculpt and stain shotcrete. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 3 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring 4 3 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 3 3 Liability concerns Most Important: 1 2 Risk acknowledgment Least Important: 5 Least Important: 5 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 10 0 10 Geotechnical drilling 100 100 100

126 Design Practices for Rock Slopes and Rockfall Management Geotechnical instrumentation 5 0 10 Geophysical methods 0 0 0 Specialized rock laboratory testing 5 80 80 Oriented borehole imagery or oriented coring 5 10 0 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 50 60 50 Deterministic slope stability models Probabilistic slope stability models Point cloud analysis 5 0 10 2-D Rockfall modeling and containment % 30 30 50 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 80 80 80 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: SD, Agency: South Dakota DOT. Title: Geotechnical Coordinator Road Miles: 500: Rock Slope Count Estimate: 500 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 70; Periodic Maintenance: 5; With rockfall mitigation and good function: 0; With rockfall mitigation and poor function: 0; Reconstructed: 5; New Construction: 20 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 100; Consultants: ; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 0; Consultants: 100; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: No, we have no design standards, but we use consistent approaches to develop rock slope and rockfall mitigation designs. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q3: Do standards vary between roadway classification or other particulars? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction

Individual Survey Responses 127   Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 2 Constructability 2 2 Funding source 4 3 Long-term maintenance Most Important: 1 Most Important: 1 Asset management 4 Aesthetics 3 2 Life-cycle costs 4 3 Resilience initiatives 4 3 Risk management plans 3 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 75%–90%. Techniques used: Other: Limiting overbreak and rockfall. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 3 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 2 Risk reduction through visual monitoring 4 3 Risk reduction through instrumentation 4 3 Fiscal impacts of poor performance 3 3 Liability concerns 2 2 Risk acknowledgment 4 2 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 10 10 0 Geotechnical instrumentation 0 0 0 Geophysical methods 75 75 5 Specialized rock laboratory testing 0 0 0 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 0 0 0 Stereonet and kinematic analyses 1 0 0 Deterministic slope stability models 0 0 0 Probabilistic slope stability models 0 0 0 Point cloud analysis 0 0 0

128 Design Practices for Rock Slopes and Rockfall Management 2-D Rockfall modeling and containment % 0 0 0 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 0 0 0 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? Not applicable Part F, Q3: Would your DOT be interested in participating as a case history? No State: TN, Agency: Tennessee DOT. Title: Civil Engineering Manager 2 Road Miles: 15,000: Rock Slope Count Estimate: 2,000 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 50; Periodic Maintenance: 10; With rockfall mitigation and good function: 10; With rockfall mitigation and poor function: 0; Reconstructed: 10; New Construction: 20 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 25; Consultants: 65; Construction contractor: 10; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 65; Consultants: 35; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, we only have design standards for new cut slopes. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by another metric (describe below). Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 1998 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item State or Interstate Percentage of ditch containment 90 Percentage of impact 95 Percentage of reduction 0 Roadside ditch width 21' minimum Target scoring RHRS for above 300 Frequency of rocks reaching road N/A Maintenance activity frequency Infrequent Probabilistic measures N/A Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 3

Individual Survey Responses 129   Constructability 3 3 Funding source 3 Most Important: 1 Long-term maintenance 2 3 Asset management 3 2 Aesthetics 4 4 Life-cycle costs 2 3 Resilience initiatives 3 3 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Staining of steel products. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 2 Consequence of major slope failure Most Important: 1 2 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 4 4 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 2 2 Liability concerns 2 2 Risk acknowledgment Least Important: 5 4 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 Rope-based reconnaissance 0 Geotechnical drilling 65 Geotechnical instrumentation 0 Geophysical methods 10 Specialized rock laboratory testing 25 Oriented borehole imagery or oriented coring 0 Rock mass characterization methods 50 Stereonet and kinematic analyses 0 Deterministic slope stability models 40 Probabilistic slope stability models 0 Point cloud analysis 0 2-D Rockfall modeling and containment % 40 3-D Rockfall modeling and containment % 0 Design guides and containment % 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes

130 Design Practices for Rock Slopes and Rockfall Management State: UT, Agency: Utah DOT. Title: Geological Engineer Road Miles: ; Rock Slope Count Estimate: 2,600 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 10; Periodic Maintenance: 80; With rockfall mitigation and good function: 6; With rockfall mitigation and poor function: 2; Reconstructed: 1; New Construction: 1 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 20; Consultants: 80; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 80; Consultants: 10; Construction contractor: 10; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by highway functional classification (interstate, major arterial, minor collector, etc.). Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? 2008 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Interstate Routes Non-Interstate Routes Percentage of ditch containment 98 95% Percentage of impact 0 Percentage of reduction 0 Roadside ditch width Per ODOT Rockfall Catchment Area Design Guide/Ritchie Ditch Per ODOT Rockfall Catchment Area Design Guide/Ritchie Ditch Target scoring N/A Frequency of rocks reaching road N/A Maintenance activity frequency N/A Probabilistic measures N/A Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 4 4 Constructability Most Important: 1 Most Important: 1 Funding source 4 Most Important: 1 Long-term maintenance Most Important: 1 Most Important: 1 Asset management Most Important: 1 2 Aesthetics Most Important: 1 Most Important: 1 Life-cycle costs 2 2 Resilience initiatives 2 2 Risk management plans 2 4

Individual Survey Responses 131   Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 75%–90%. Techniques used: Other: Choosing the least visible option. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 4 3 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 4 4 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 0 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment 3 3 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 10 0 10 Geotechnical drilling 80 80 0 Geotechnical instrumentation 10 0 0 Geophysical methods 50 50 0 Specialized rock laboratory testing 80 80 0 Oriented borehole imagery or oriented coring 70 50 0 Rock mass characterization methods 70 80 0 Stereonet and kinematic analyses 80 80 0 Deterministic slope stability models 70 80 0 Probabilistic slope stability models 10 0 0 Point cloud analysis 0 0 70 2-D Rockfall modeling and containment % 80 100 100 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 80 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: VA, Agency: FHWA. Title: Division Geotechnical Engineer Road Miles: 2,500: Rock Slope Count Estimate: 300 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 10; Periodic Maintenance: 80; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 0; Reconstructed: 5; New Construction: 0 Part C, Q5: Designer percentages of new rock cut slopes.

132 Design Practices for Rock Slopes and Rockfall Management In-House: 0; Consultants: 0; Construction contractor: 100; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 50; Consultants: 50; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Not applicable; we do not have rock slope or rockfall design standards. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? N/A Part D, Q6 & Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment N/A N/A Percentage of impact 0 N/A Percentage of reduction 0 0 Roadside ditch width N/A N/A Target scoring N/A N/A Frequency of rocks reaching road N/A N/A Maintenance activity frequency N/A N/A Probabilistic measures N/A N/A Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 3 Constructability Most Important: 1 Most Important: 1 Funding source 3 3 Long-term maintenance 2 2 Asset management 3 3 Aesthetics 3 3 Life-cycle costs 3 3 Resilience initiatives 3 2 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Contouring of wire mesh/nets to the slope. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs Most Important: 1 Most Important: 1 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 2 Most Important: 1

Individual Survey Responses 133   Fiscal impacts of poor performance 2 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment Most Important: 1 Most Important: 1 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 90 100 Rope-based reconnaissance 0 0 0 Geotechnical drilling 0 0 0 Geotechnical instrumentation 0 0 0 Geophysical methods 0 10 0 Specialized rock laboratory testing 0 0 0 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 0 0 0 Stereonet and kinematic analyses 90 0 90 Deterministic slope stability models 0 0 0 Probabilistic slope stability models 0 0 0 Point cloud analysis 0 10 0 2-D Rockfall modeling and containment % 90 0 90 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 90 90 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? Not applicable Part F, Q3: Would your DOT be interested in participating as a case history? No State: VA, Agency: Virginia DOT. Title: Engineering Geologist Road Miles: 58,000: Rock Slope Count Estimate: 4,000 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 10; Periodic Maintenance: 50; With rockfall mitigation and good function: 10; With rockfall mitigation and poor function: 5; Reconstructed: 10; New Construction: 15 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 25; Consultants: 75; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 25; Consultants: 50; Construction contractor: 25; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts.

134 Design Practices for Rock Slopes and Rockfall Management Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by highway functional classification (interstate, major arterial, minor collector, etc.). Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? 2012 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Interstate Primary Percentage of ditch containment 100 (i.e., no rockfall in pavement) 100 (i.e., no rockfall in pavement) Percentage of impact 0 0 Percentage of reduction 100 100 Roadside ditch width As per specific design As per specific design Target scoring N/A Frequency of rocks reaching road 0 0 Maintenance activity frequency 0 0 Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5 Constructability 4 2 Funding source 4 3 Long-term maintenance 2 2 Asset management 3 2 Aesthetics 3 2 Life-cycle costs 2 2 Resilience initiatives 2 2 Risk management plans Most Important: 1 Most Important: 1 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 90%–100%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Removing proximal ends of rock bolts. Other: Stained shotcrete or other facing. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 2 Least Important: 5 Fiscal impacts of poor performance 2 4 Liability concerns 4 4 Risk acknowledgment 4 4 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation.

Individual Survey Responses 135   Surface reconnaissance 100 10 100 Rope-based reconnaissance 10 5 10 Geotechnical drilling 100 100 0 Geotechnical instrumentation 5 5 0 Geophysical methods 50 10 0 Specialized rock laboratory testing 5 5 5 Oriented borehole imagery or oriented coring 1 5 0 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 100 100 100 Deterministic slope stability models 100 100 100 Probabilistic slope stability models 100 100 100 Point cloud analysis 5 5 5 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: VT, Agency: Vermont Agency of Transportation. Title: AOT Geologist Road Miles: 16,395: Rock Slope Count Estimate: 3,666 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 60; Periodic Maintenance: 25; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 2; Reconstructed: 4; New Construction: 4 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 30; Consultants: 70; Construction contractor: 0; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 30; Consultants: 70; Construction contractor: 0; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, informal standards have been communicated between agency geotechnical personnel. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, rock slope design standards are the same for rockfall mitigation as they are for new cuts. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Design Tool Exposed Rock Unexposed Rock Rockfall

136 Design Practices for Rock Slopes and Rockfall Management Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 3 Constructability Most Important: 1 Most Important: 1 Funding source Most Important: 1 Most Important: 1 Long-term maintenance Most Important: 1 2 Asset management 2 2 Aesthetics 3 3 Life-cycle costs 2 2 Resilience initiatives 2 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 25%–50%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Removing proximal ends of rock bolts. Other: staining shotcrete to match local rock color. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 3 3 Fiscal impacts of poor performance 0 Most Important: 1 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment 2 2 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 50 0 50 Geotechnical drilling 10 100 0 Geotechnical instrumentation 10 50 0 Geophysical methods 10 80 20 Specialized rock laboratory testing 50 50 50 Oriented borehole imagery or oriented coring 10 100 0 Rock mass characterization methods 50 100 10 Item

Individual Survey Responses 137   Stereonet and kinematic analyses 100 100 100 Deterministic slope stability models 100 100 100 Probabilistic slope stability models 100 100 100 Point cloud analysis 50 0 80 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? Not applicable Part F, Q3: Would your DOT be interested in participating as a case history? No State: WA, Agency: Washington State DOT. Title: Interim Chief Engineering Geologist Road Miles: 7,500: Rock Slope Count Estimate: 1,360 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 0; Periodic Maintenance: 83; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 5; Reconstructed: 5; New Construction: 2 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 94; Consultants: 5; Construction contractor: 1; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 94; Consultants: 5; Construction contractor: 1; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? No Part D, Q5: What year were standards adopted? 2005 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures

138 Design Practices for Rock Slopes and Rockfall Management Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5 Constructability Most Important: 1 Most Important: 1 Funding source Most Important: 1 Most Important: 1 Long-term maintenance 2 2 Asset management 2 2 Aesthetics 2 2 Life-cycle costs 2 2 Resilience initiatives 2 2 Risk management plans 2 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 25%–50%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Hammering out half casts on cut slopes. Removing proximal ends of rock bolts. Other: Permeon treatment of rock slope where it was scaled. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 3 3 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring 2 2 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 3 3 Liability concerns 4 4 Risk acknowledgment 4 4 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 50 10 50 Geotechnical drilling 50 100 10 Geotechnical instrumentation 5 10 10 Geophysical methods 40 100 10 Specialized rock laboratory testing 100 100 100 Oriented borehole imagery or oriented coring 40 100 10 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 100 100 100 Deterministic slope stability models 100 100 100 Probabilistic slope stability models 25 25 25 Point cloud analysis 100 0 75 2-D Rockfall modeling and containment % 50 100 50 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 100

Individual Survey Responses 139   Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes State: WA, Agency: FHWA WFLHD. Title: WFL Geoteam Supervisor Road Miles: 0: Rock Slope Count Estimate: 0 and basis of estimate: Blank Part C, Q4: Rock Slope Condition Percentages No Maintenance: 28; Periodic Maintenance: 50; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 2; Reconstructed: 12; New Construction: 3 Part C, Q5: Designer percentages of new rock cut slopes. In-House: 55; Consultants: 40; Construction contractor: 5; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 58; Consultants: 40; Construction contractor: 2; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, standards have been developed but not documented as formal department policy. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by another metric (describe below). Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? 2005 Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item State or County Partner Federal Land Management Partner Percentage of ditch containment 90 85 Percentage of impact 99 99 Percentage of reduction Roadside ditch width RCAD guidance or state requirements used RCAD guidance Target scoring Frequency of rocks reaching road Maintenance activity frequency Hopefully reduce it; but contain to ditch is the goal. Hopefully reduce it; but contain the big rocks to the ditch is the goal. Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5

140 Design Practices for Rock Slopes and Rockfall Management Constructability Most Important: 1 Most Important: 1 Funding source 2 2 Long-term maintenance 2 Most Important: 1 Asset management 3 3 Aesthetics Most Important: 1 Life-cycle costs 4 2 Resilience initiatives 3 2 Risk management plans Most Important: 1 2 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 75%–90%. Techniques used: Staining of steel products. Contouring of wire mesh/nets to the slope. Hammering out half casts on cut slopes. Removing proximal ends of rock bolts. Other: rock painting and staining following scaling activities. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 4 4 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 Most Important: 1 Risk reduction through visual monitoring Most Important: 1 Most Important: 1 Risk reduction through instrumentation Least Important: 5 Least Important: 5 Fiscal impacts of poor performance 2 3 Liability concerns 2 2 Risk acknowledgment 2 Most Important: 1 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 5 0 10 Geotechnical drilling 25 100 10 Geotechnical instrumentation 25 100 10 Geophysical methods 5 100 10 Specialized rock laboratory testing 15 30 5 Oriented borehole imagery or oriented coring 5 10 0 Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 100 100 100 Deterministic slope stability models 100 100 100 Probabilistic slope stability models 25 100 100 Point cloud analysis 50 25 50 2-D Rockfall modeling and containment % 75 100 100 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? Yes

Individual Survey Responses 141   State: WI, Agency: Wisconsin DOT. Title: Geologist Road Miles: ; Rock Slope Count Estimate: 300 and basis of estimate: Experience Part C, Q4: Rock Slope Condition Percentages No Maintenance: 20; Periodic Maintenance: 80; With rockfall mitigation and good function: 0; With rockfall mitigation and poor function: 0; Reconstructed: ; New Construction: Part C, Q5: Designer percentages of new rock cut slopes. In-House: 35; Consultants: 65; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 40; Consultants: 40; Construction contractor: 20; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, informal standards that may be applied on a project- specific basis. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, we only have design standards for new cut slopes. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by another metric (describe below). Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? Informal standard in 2002 (after ODOT Rockfall Catchment Area Design Guide published) Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Rockslope Design Along Interstate or High ADT State Divided Highway Percentage of ditch containment 90 Percentage of impact Percentage of reduction Roadside ditch width Based on ODOT Rockfall Catchment Area Design Guide Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method Least Important: 5 Least Important: 5 Constructability 2 2 Funding source 4 4 Long-term maintenance 3 3 Asset management Aesthetics Least Important: 5 Least Important: 5 Life-cycle costs 2 2 Resilience initiatives 4 Risk management plans Most Important: 1 Most Important: 1

142 Design Practices for Rock Slopes and Rockfall Management Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Not applicable. Techniques used: Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 2 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 3 3 Risk reduction through visual monitoring 4 4 Risk reduction through instrumentation 4 4 Fiscal impacts of poor performance 2 2 Liability concerns 2 2 Risk acknowledgment Least Important: 5 Least Important: 5 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance Geotechnical drilling 100 100 100 Geotechnical instrumentation 10 10 50 Geophysical methods 30 30 10 Specialized rock laboratory testing 30 30 30 Oriented borehole imagery or oriented coring Rock mass characterization methods 100 100 100 Stereonet and kinematic analyses 10 10 Deterministic slope stability models Probabilistic slope stability models Point cloud analysis 10 10 20 2-D Rockfall modeling and containment % 10 10 20 3-D Rockfall modeling and containment % Design guides and containment % 100 100 75 Part F, Q1: Do you have performance measures specific to rock slopes? No Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: WV, Agency: West Virginia Division of Highways. Title: Geotechnical Unit Leader Road Miles: 38,770: Rock Slope Count Estimate: and basis of estimate: Blank Part C, Q4: Rock Slope Condition Percentages No Maintenance: 50; Periodic Maintenance: 20; With rockfall mitigation and good function: 5; With rockfall mitigation and poor function: 10; Reconstructed: 5; New Construction: 10 Part C, Q5: Designer percentages of new rock cut slopes.

Individual Survey Responses 143   In-House: 10; Consultants: 65; Construction contractor: 25; Manufacturer: 0 Part C, Q6: Designer percentages of rockfall mitigation. In-House: 25; Consultants: 10; Construction contractor: 65; Manufacturer: 0 Part D, Q1: Adoption of minimum design standards: Yes, formal standards have been developed and documented. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? No, we only have design standards for new cut slopes. Part D, Q3: Do standards vary between roadway classification or other particulars? Yes, separated by highway functional classification (interstate, major arterial, minor collector, etc.). Part D, Q4: Standards applicable to appurtenant facilities? Yes Part D, Q5: What year were standards adopted? N/A Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item Percentage of ditch containment Percentage of impact Percentage of reduction Roadside ditch width Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important,5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 4 3 Constructability Most Important: 1 Most Important: 1 Funding source Most Important: 1 2 Long-term maintenance Most Important: 1 Most Important: 1 Asset management 3 3 Aesthetics 3 2 Life-cycle costs 2 2 Resilience initiatives 3 3 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: Less than 25%. Techniques used: Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 0 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs Most Important: 1 2 Risk reduction through visual monitoring 3 2 Risk reduction through instrumentation 4 4

144 Design Practices for Rock Slopes and Rockfall Management Fiscal impacts of poor performance 2 2 Liability concerns Most Important: 1 Most Important: 1 Risk acknowledgment Most Important: 1 Most Important: 1 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation. Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 100 100 Rope-based reconnaissance 0 0 5 Geotechnical drilling 75 95 25 Geotechnical instrumentation 0 0 0 Geophysical methods 5 5 0 Specialized rock laboratory testing 75 90 25 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 80 100 50 Stereonet and kinematic analyses 10 10 20 Deterministic slope stability models 0 0 20 Probabilistic slope stability models 0 0 0 Point cloud analysis 5 10 10 2-D Rockfall modeling and containment % 25 33 80 3-D Rockfall modeling and containment % 0 0 10 Design guides and containment % 90 90 100 Part F, Q1: Do you have performance measures specific to rock slopes? No. Comment: Performed at our district level. Part F, Q2: Do you regularly engage in performance data collection efforts? No Part F, Q3: Would your DOT be interested in participating as a case history? No State: WY, Agency: Wyoming DOT. Title: Chief Engineering Geologist Road Miles: 6,859: Rock Slope Count Estimate: 410 and basis of estimate: Comprehensive inventory Part C, Q4: Rock Slope Condition Percentages No Maintenance: 5; Periodic Maintenance: 67; With rockfall mitigation and good function: 15; With rockfall mitigation and poor function: 2; Reconstructed: 10; New Construction: 1 Part C, Q5: Designer percentages of new rock cut slopes. In-House: ; Consultants: ; Construction contractor: ; Manufacturer: Part C, Q6: Designer percentages of rockfall mitigation. In-House: 70; Consultants: 30; Construction contractor: ; Manufacturer: Part D, Q1: Adoption of minimum design standards: Yes, informal standards have been communicated between agency geotechnical personnel. Part D, Q2: Do standards vary between new cuts and rockfall mitigation? Yes, design standards are unique between designs for new cuts and rockfall mitigation.

Individual Survey Responses 145   Part D, Q3: Do standards vary between roadway classification or other particulars? No, rock slope design standards are consistent across roadway classifications. Part D, Q4: Standards applicable to appurtenant facilities? Not applicable Part D, Q5: What year were standards adopted? It has been an evolving process since the development of the Rockfall Catchment Area Design Guide in 2001. Part D, Q6 and Q7: Design standards for classification. Note: Blank when not entered by respondent. Item All Percentage of ditch containment 95 Percentage of impact 90 Percentage of reduction 0 Roadside ditch width Minimum width, Green Book clear zone Target scoring Frequency of rocks reaching road Maintenance activity frequency Probabilistic measures Part E, Q1 and Q2: Relative importance for technical considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Project delivery method 3 2 Constructability Most Important: 1 Most Important: 1 Funding source 2 Most Important: 1 Long-term maintenance 2 2 Asset management 4 3 Aesthetics 3 4 Life-cycle costs 2 3 Resilience initiatives 3 3 Risk management plans 3 3 Part E, Q3 and Q4: Aesthetics: Percentage of projects where aesthetics are considered: 25%–50%. Techniques used: Staining of steel products. Part E, Q5 and Q6: Relative importance for risk considerations, 1 = Most Important, 5 = Least Important. Consideration New Cut Slopes Rockfall Mitigation Consequence of minor slope failure 2 Most Important: 1 Consequence of major slope failure Most Important: 1 Most Important: 1 Maintenance frequency and costs 2 2 Risk reduction through visual monitoring 3 3 Risk reduction through instrumentation Least Important: 5 4 Fiscal impacts of poor performance 3 4 Liability concerns 4 4 Risk acknowledgment 4 4 Part E, Q7, Q8, and Q9: Design tool use between new cut slopes with exposed rock, minimally or not exposed rock, and for rockfall mitigation.

146 Design Practices for Rock Slopes and Rockfall Management Design Tool Exposed Rock Unexposed Rock Rockfall Surface reconnaissance 100 0 100 Rope-based reconnaissance 20 0 30 Geotechnical drilling 50 50 10 Geotechnical instrumentation 0 0 0 Geophysical methods 20 50 0 Specialized rock laboratory testing 50 50 10 Oriented borehole imagery or oriented coring 0 0 0 Rock mass characterization methods 100 50 100 Stereonet and kinematic analyses 100 100 100 Deterministic slope stability models 0 0 0 Probabilistic slope stability models 0 0 0 Point cloud analysis 50 50 50 2-D Rockfall modeling and containment % 100 100 100 3-D Rockfall modeling and containment % 0 0 0 Design guides and containment % 100 100 100 Part F, Q1: Do you have performance measures specific to rock slopes? Yes, informally tracked by our geotechnical group. Comment: We are in the process of developing a GAM system for rock slopes. Part F, Q2: Do you regularly engage in performance data collection efforts? No. Comment: We don’t now, but it will be included as a long-term goal in the GAM system. Part F, Q3: Would your DOT be interested in participating as a case history? No